1-Ethoxy-2,3-difluor-4-[4-(trans-4-propylcyclohexyl)-1-cyclohexen-1-yl]-benzene

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

Sep 01, 2009 - Oct 07, 2009

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 C (Ready Biodegradability: Modified MITI Test (I))

GLP compliance:

yes (incl. QA statement)

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

- Source of inoculum/activated sludge (e.g. location, sampling depth, contamination history, procedure): activated sludge, micro organisms from a domestic waste water treatment plant
- Origin: municipal sewage treatment plant
- Conditioning: The activated sludge used for this study was washed by centrifugation and the supernatant liquid phase was decanted. The solid material was re-suspended in tap water and centrifuged again. This procedure was repeated twice.
- Concentration of suspended solids per litre: 30 mg

Duration of test (contact time):

28 d

Initial conc.:

100 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

O2 consumption

Parameter followed for biodegradation estimation:

test mat. analysis

Details on study design:

According to guideline

Reference substance:

aniline

Test performance:

The reference item (aniline) was sufficiently degraded to 70 % after 14 days and to 71 % after 28 days of incubation. The validity criterion that the degradation should be > 60 % after 14 d was fulfilled.

Key result

Parameter:

% degradation (O2 consumption)

Value:

0

Sampling time:

28 d

Key result

Parameter:

% degradation (test mat. analysis)

Value:

0

Sampling time:

28 d

Results with reference substance:

14 d: 70 %, 28 d: 71 %

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Conclusions:

The degradation rate of the test material did not reach 60 % within the 10-day window and after 28 days of incubation. Thus, the test item is not readily biodegradable.

Executive summary:

Purpose

The test item was investigated for its ready biodegradability in a Manometric Respirometry Test over a period of 28 days. The biodegradation was followed by the oxygen uptake of the microorganisms during exposure. The substance concentration during the course of this study was monitored by LC with UV detection (244 nm). As a reference item aniline was tested simultaneously under the same conditions as the test item and functioned as a procedure control. The GLP study was performed according to OECD TG 301C.

 

Result

Biodegradation of test item

After correction of the mean biochemical oxygen demand of the inoculum controls at the end of the 28 -day exposure period a degradation of 0 % as found. HPLC analysis confirmed that no degradation occurs.

 

Biodegradation of aniline

The reference item was sufficiently degraded to 70 % after 14 days and to 71 % after 28 days of incubation, thus confirming the suitability of the used activated sludge inoculum.

 

Conclusion

The degradation rate of the test material did not reach 60 % within the 10 -day window and after 28 days of incubation. Thus, the test item is not readily biodegradable.

Reference 2

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

2010-08-12 to 2010-12-17

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 D (Ready Biodegradability: Closed Bottle Test)

Deviations:

not specified

GLP compliance:

yes (incl. QA statement)

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, adapted

Details on inoculum:

The inoculum was derived from the secondary effluent of Shanghai Longhua Sewage Plant. The inoculum was pre-conditioned by aerating the secondary eftluent, without other treatment or addition, for 5-7 days at the test temperature of 20 + 1 °C. Control microbe counted at the range of
10000-1000000 orgs/L.

Duration of test (contact time):

28 d

Initial conc.:

2 mg/L

Based on:

test mat.

Remarks:

final concentration was clearly above water solubility

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

TEST CONDITIONS
- Composition of medium: mineral medium
- Test temperature: 20 +/- 1 °C
- pH: 7.4
- pH adjusted: no
- Aeration of dilution water: yes
- Suspended solids concentration:
- Continuous darkness: yes

TEST SYSTEM
- Culturing apparatus: BOD bottles
- Number of culture flasks/concentration: 10
- Method used to create aerobic conditions: aeration of medium
- Test performed in closed vessels: yes
- Test performed in open system: no

SAMPLING
- Sampling frequency: on day 0, 7, 14, 21 and 28
- Sampling method: 2 bottles per group were taken for sampling every 7 days

CONTROL AND BLANK SYSTEM
- Inoculum blank: yes
- Abiotic sterile control: no
- Toxicity control: yes

Reference substance:

laurylsulfonate

Remarks:

sodium laurylsulfonate

Key result

Parameter:

% degradation (O2 consumption)

Value:

0

Sampling time:

28 d

Details on results:

Under the test conditions no biodegradation of test item could be observed.
The percentage degradation did not exceed 60 % within the 10-day window and after 28 days of incubation.
The test item is considered not readily biodegradable.

In the toxicity control containing both, test item and reference item 77 % biodegradation was noted within 14 days and 80.5 % biodegradation was determined after 28 days of incubation.

According to the test guidelines the test item can be assumed to be not inhibitory on the activated sludge micro organisms because degradation was > 25 % within 14 days.
The oxygen demand in the abiotic control was zero; no correction of the test item degradation rates had to be done.

Results with reference substance:

The reference item sodium laurylsulfonate was sufficiently degraded to 76.5 % after 14 days and to 79.5 % after 28 days of incubation. The percentage degradation of the reference item confirms the suitability of the used activated sludge inoculum.

Validity criteria fulfilled:

yes

Interpretation of results:

under test conditions no biodegradation observed

Conclusions:

Under the test conditions no biodegradation of test item could be observed. The percentage degradation did not exceed 60 % within the 10-day window and after 28 days of incubation. The test item is considered not readily biodegradable.

Executive summary:

In this OECD 301D Assay the results show no biodegradation of test item.

 

The percentage degradation did not exceed 60 % within the 10-day window and after 28 days of incubation.

 

The test item is considered not readily biodegradable.

 

The reference item sodium laurylsulfonate was sufficiently degraded to 76.5 % after 14 days and to 79.5 % after 28 days of incubation. The percentage degradation of the reference item confirms the suitability of the used activated sludge inoculum.

 

In the toxicity control containing both, test item and reference item 77 % biodegradation was noted within 14 days and 80.5 % biodegradation was determined after 28 days of incubation.

 

According to the test guidelines the test item can be assumed to be not inhibitory on the activated sludge micro organisms because degradation was > 25 % within 14 days.

The oxygen demand in the abiotic control was zero; no correction of the test item degradation rates had to be done.

Description of key information

The test item is not considered to be readily biodegradable according to OECD 301D and OECD 301C.

Key value for chemical safety assessment

Biodegradation in water:

under test conditions no biodegradation observed

Type of water:

freshwater

Additional information

Two experimental studies are available to address the endpoint for the substance. They are considered together.

 

OECD 301C

Purpose

The test item was investigated for its ready biodegradability in a Manometric Respirometry Test over a period of 28 days. The biodegradation was followed by the oxygen uptake of the microorganisms during exposure. The substance concentration during the course of this study was monitored by LC with UV detection (244 nm). As a reference item aniline was tested simultaneously under the same conditions as the test item and functioned as a procedure control. The GLP study was performed according to OECD 301C.

 

Result

Biodegradation of test item

After correction of the mean biochemical oxygen demand of the inoculum controls at the end of the 28 -day exposure period a degradation of 0 % as found. HPLC analysis confirmed that no degradation occurs.

 

Biodegradation of aniline

The reference item was sufficiently degraded to 70 % after 14 days and to 71 % after 28 days of incubation, thus confirming the suitability of the used activated sludge inoculum.

 

Conclusion

The degradation rate of the test material did not reach 60 % within the 10 -day window and after 28 days of incubation. Thus, the test item is not readily biodegradable.

 

OECD 301F

In this OECD 301D Assay the results show no biodegradation of test item. The percentage degradation did not exceed 60 % within the 10-day window and after 28 days of incubation. The test item is considered not readily biodegradable. The reference item sodium laurylsulfonate was sufficiently degraded to 76.5 % after 14 days and to 79.5 % after 28 days of incubation. The percentage degradation of the reference item confirms the suitability of the used activated sludge inoculum. In the toxicity control containing both, test item and reference item 77 % biodegradation was noted within 14 days and 80.5 % biodegradation was determined after 28 days of incubation. According to the test guidelines the test item can be assumed to be not inhibitory on the activated sludge microorganisms because degradation was > 25 % within 14 days. The oxygen demand in the abiotic control was zero; no correction of the test item degradation rates had to be done.

 

Based on the results of the studies the test item is considered not readily biodegradable.